What constitutes a "context" in Pose mode?
From the keying sets documentation:

No suitable context info for Keying Set
This error occurs when either:

The Keying Set requires that some specific type of data is selected (i.e. all builtin Keying Sets require that you have some selected object/bone)
When using the &quot;Available&quot; builtin Keying Set, and the object that you're trying to keyframe doesn't already have any keyframes/F-Curves, this error will be shown as it there are no existing keyframes/F-Curve on the selected object(s) to insert keyframes on


The keying set can be selected/cleared using the  in the header of the Timeline window.